/Engine/Source/Runtime/Engine/Classes/Sound/SoundWave.h
Returns the loading behavior we should use for this sound wave. If this is called withinSerialize(), this should be called with bCheckSoundClasses = false, Since there is no guarantee that the deserialized USoundClasses have been resolved yet.
ESoundWaveLoadingBehavior GetLoadingBehavior ( bool bCheckSoundClasses ) const